Microstructured optical fiber and preform for same having specific oxygen deficiency center and chlorine concentrations

Abstract

The invention relates to microstructured optical fibers that are drawn through hollow channels and have a core region, which extends along a fiber longitudinal axis, and a jacket region surrounding the core region. The aim of the invention is to reduce a damping increase due to corrosion and to reduce the emission of chlorine on the basis of the microstructured optical fibers. This is achieved in that at least some of the hollow channels are delimited by a wall material made of synthetic quartz glass which has a chlorine concentration of less than 300 wt. ppm and oxygen deficiency centers in a concentration of at least 2×1015 cm-3.

The invention claimed is: 
     
         1 . A microstructured optical fiber which has a core region extending along a longitudinal axis of the microstructured optical fiber and an inner cladding region surrounding the core region, and through which hollow channels run, of which at least some are bordered by a wall material made of synthetic quartz glass which has a chlorine concentration of less than 300 ppm by weight, wherein the synthetic quartz glass of the wall material has oxygen deficiency centers at a concentration of at least 2×10 15  cm −3 . 
     
     
         2 . The microstructured optical fiber according to  claim 1 , wherein the synthetic quartz glass has a concentration of oxygen deficiency centers of at least 5×10 15  cm −3  better 1×10 16  cm −3 , and preferably at least 5×10 16  cm −3 . 
     
     
         3 . The microstructured optical fiber according to  claim 1 , wherein the synthetic quartz glass contains oxygen deficiency centers at a concentration of at most 2×10 20  cm −3 , preferably at most 5×10 19  cm −3 , at most 1×10 19  cm −3 , at most 5×10 18  cm −3 , at most 2×10 18  cm −3 , at most 1×10 18  cm −3 , at most 5×10 17  cm −3 , at most 2×10 17  cm −3  and particularly preferably at most 1×10 17  cm −3 . 
     
     
         4 . The microstructured optical fiber according to  claim 1 , wherein the synthetic quartz glass has a hydroxyl group content of less than 10 ppm by weight, preferably less than 1 ppm by weight. 
     
     
         5 . The microstructured optical fiber according to  claim 4 , wherein the synthetic quartz glass has a halogen content of less than 20 ppm by weight, preferably less than 10 ppm by weight. 
     
     
         6 . The microstructured optical fiber according to  claim 1 , wherein the synthetic quartz glass contains foreign substances, except for carbon and nitrogen, at an overall concentration of less than 30 ppm by weight, preferably less than 3 ppm by weight. 
     
     
         7 . The microstructured optical fiber according to  claim 1 , wherein the synthetic quartz glass has a viscosity at a temperature of 1200° C. of at least 10 13  dPa s. 
     
     
         8 . The microstructured optical fiber according to  claim 1 , wherein the core region has at least one hollow core, the inner cladding region comprises a microstructured regular arrangement of hollow channels extending in a longitudinal direction, and in that the inner cladding region is made of the wall material. 
     
     
         9 . The microstructured optical fiber according to  claim 1 , wherein the core region has at least one hollow core, and the inner cladding region comprises hollow structural elements extending in a direction of the longitudinal axis of the microstructured optical fiber which are arranged annularly on the inner lateral surface of an inner cladding, and which guide light by an anti-resonance effect along the hollow core. 
     
     
         10 . The microstructured optical fiber according to  claim 9 , wherein the hollow structural elements each comprise an anti-resonance element (ARE) outer capillary and at least one nested element (NE) inner capillary connected to an inner lateral surface of the ARE outer capillary, and in that the inner cladding, the ARE outer capillary and/or the at least one NE inner capillary are made from the wall material. 
     
     
         11 . The microstructured optical fiber according to  claim 9 , wherein it comprises an outer cladding region surrounding the inner cladding region, which outer cladding region is made of the wall material. 
     
     
         12 . A preform for producing a microstructure optical fiber according to  claim 1 , wherein the preform has a core region extending along a preform longitudinal axis and an inner cladding region surrounding the core region, and through which hollow channels run, of which at least some are bordered by a wall material made of synthetically produced quartz glass, which has a chlorine concentration of less than 300 ppm by weight and oxygen deficiency centers at a concentration of at least 2×10 15  cm −3 .